全文获取类型
收费全文 | 96篇 |
免费 | 16篇 |
专业分类
112篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 1篇 |
2005年 | 8篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1984年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有112条查询结果,搜索用时 15 毫秒
1.
2.
Genetic and physical mapping of a novel region close to the fragile X site on the human X chromosome 总被引:11,自引:0,他引:11
M. N. Patterson M. V. Bell J. Bloomfield T. Flint H. Dorkins S. N. Thibodeau D. Schaid G. Bren C. E. Schwartz b. Wieringa H. -H. Ropers D. F. Callen G. Sutherland U. Froster-Iskenius H. Vissing K. E. Davies 《Genomics》1989,4(4):570-578
We report the isolation and characterization of a novel DNA marker (1A1) in Xqter in the region of the fragile X. Genetic studies in families segregating for the fragile X syndrome suggest that 1A1 lies between the disease mutation and the distal locus, DXS52. Studies in normal and fragile X families show that 1A1 is tightly linked to DXS52 (Zmax = 17.20; theta max = 0.03) and F8 (Zmax = 7.01; theta max = 0.08). Multipoint mapping of families supports the order Xcen-DXS105-FRAXA-1A1-DXS52-(F8, DXS115)-Xqter. Pulsed-field gel electrophoresis (PFGE) studies demonstrate that 1A1 defines a new region of at least 2 Mb of DNA not physically linked to DXS52 or F8, thus extending the physical map of Xq27-qter to over 4 Mb. Complex partial digestion PFGE patterns, probably due to differing degrees of methylation, are observed with 1A1 in unrelated normal and fragile-X-positive individuals, whereas other distal markers give uniform digestion profiles. Physical data suggest that 1A1 lies in a region less CpG rich than other distal markers in Xq27-qter. 相似文献
3.
4.
L. Banci I. Bertini K. L. Bren M. A. Cremonini H. B. Gray C. Luchinat P. Turano 《Journal of biological inorganic chemistry》1996,1(2):117-126
The availability of NOE constraints and of the relative solution structure of a paramagnetic protein permits the use of pseudocontact
shifts as further structural constraints. We have developed a strategy based on: (1) determination of the χ tensor anisotropy
parameters from the starting structure; (2) recalculation of a new structure by using NOE and pseudocontact shift constraints simultaneously; (3) redetermination of the χ tensor anisotropy parameters from the new structure,
and so on until self-consistency. The system investigated is the cyanide derivative of a variant of the oxidized Saccharomyces cerevisiae iso-1-cytochrome c containing the Met80Ala mutation. The structure has been substantially refined. It is shown that the analysis of the deviation
of the experimental pseudocontact shifts from those calculated using the starting structure may be unsound, as may the simple
structure refinement based on the pseudocontact shift constraints only.
Received: 11 July 1995 / Accepted: 30 October 1995 相似文献
5.
Demin Konstantin A. Refeld Aleksandr G. Bogdanova Anna A. Prazdnova Evgenya V. Popov Igor V. Kutsevalova Olga Yu. Ermakov Alexey M. Bren Anzhelica B. Rudoy Dmitry V. Chistyakov Vladimir A. Weeks Richard Chikindas Michael L. 《Probiotics and antimicrobial proteins》2021,13(4):926-948
Probiotics and Antimicrobial Proteins - Pathogenic Candida and infections caused by those species are now considered as a serious threat to public health. The treatment of candidiasis is... 相似文献
6.
Leeat Keren Ora Zackay Maya Lotan‐Pompan Uri Barenholz Erez Dekel Vered Sasson Guy Aidelberg Anat Bren Danny Zeevi Adina Weinberger Uri Alon Ron Milo Eran Segal 《Molecular systems biology》2013,9(1)
Most genes change expression levels across conditions, but it is unclear which of these changes represents specific regulation and what determines their quantitative degree. Here, we accurately measured activities of ~900 S. cerevisiae and ~1800 E. coli promoters using fluorescent reporters. We show that in both organisms 60–90% of promoters change their expression between conditions by a constant global scaling factor that depends only on the conditions and not on the promoter's identity. Quantifying such global effects allows precise characterization of specific regulation—promoters deviating from the global scale line. These are organized into few functionally related groups that also adhere to scale lines and preserve their relative activities across conditions. Thus, only several scaling factors suffice to accurately describe genome‐wide expression profiles across conditions. We present a parameter‐free passive resource allocation model that quantitatively accounts for the global scaling factors. It suggests that many changes in expression across conditions result from global effects and not specific regulation, and provides means for quantitative interpretation of expression profiles. 相似文献
7.
Mazanko Maria S. Makarenko Maksim S. Chistyakov Vladimir A. Usatov Alexander V. Prazdnova Evgeniya V. Bren Anzhelika B. Gorlov Ivan F. Komarova Zoya B. Weeks Richard Chikindas Michael L. 《Probiotics and antimicrobial proteins》2019,11(4):1324-1329
Probiotics and Antimicrobial Proteins - A promising approach for slowing down the rate of reproductive aging is the use of probiotic bacteria as a feed additive. In the current study was... 相似文献
8.
Michael M. H. Graf Lin Zhixiong Urban Bren Dietmar Haltrich Wilfred F. van Gunsteren Chris Oostenbrink 《PLoS computational biology》2014,10(12)
The flavoenzyme pyranose dehydrogenase (PDH) from the litter decomposing fungus Agaricus meleagris oxidizes many different carbohydrates occurring during lignin degradation. This promiscuous substrate specificity makes PDH a promising catalyst for bioelectrochemical applications. A generalized approach to simulate all 32 possible aldohexopyranoses in the course of one or a few molecular dynamics (MD) simulations is reported. Free energy calculations according to the one-step perturbation (OSP) method revealed the solvation free energies (ΔGsolv) of all 32 aldohexopyranoses in water, which have not yet been reported in the literature. The free energy difference between β- and α-anomers (ΔGβ-α) of all d-stereoisomers in water were compared to experimental values with a good agreement. Moreover, the free-energy differences (ΔG) of the 32 stereoisomers bound to PDH in two different poses were calculated from MD simulations. The relative binding free energies (ΔΔGbind) were calculated and, where available, compared to experimental values, approximated from K
m values. The agreement was very good for one of the poses, in which the sugars are positioned in the active site for oxidation at C1 or C2. Distance analysis between hydrogens of the monosaccharide and the reactive N5-atom of the flavin adenine dinucleotide (FAD) revealed that oxidation is possible at HC1 or HC2 for pose A, and at HC3 or HC4 for pose B. Experimentally detected oxidation products could be rationalized for the majority of monosaccharides by combining ΔΔGbind and a reweighted distance analysis. Furthermore, several oxidation products were predicted for sugars that have not yet been tested experimentally, directing further analyses. This study rationalizes the relationship between binding free energies and substrate promiscuity in PDH, providing novel insights for its applicability in bioelectrochemistry. The results suggest that a similar approach could be applied to study promiscuity of other enzymes. 相似文献
9.
AB Chang NC Cox J Purcell JM Marchant PJ Lewindon GJ Cleghorn LC Ee GD Withers MK Patrick J Faoagali 《Respiratory research》2005,6(1):1-5
Background and methods
Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.Results
We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 105 viral copies/ml in nasal lavage and 1.88 × 105 viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.Conclusion
HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely. 相似文献10.
McRee DE Williams PA Sridhar V Pastuszyn A Bren KL Patel KM Chen Y Todaro TR Sanders D Luna E Fee JA 《The Journal of biological chemistry》2001,276(9):6537-6544
Cytochrome rC(557) is an improperly matured, dimeric cytochrome c obtained from expression of the "signal peptide-lacking" Thermus thermophilus cycA gene in the cytoplasm of Escherichia coli. It is characterized by its Q(00) (or alpha-) optical absorption band at 557 nm in the reduced form (Keightley, J. A., Sanders, D., Todaro, T. R., Pastuszyn, A., and Fee, J. A. (1998) J. Biol. Chem. 273, 12006-12016). We report results of a broad ranging, biochemical and spectral characterization of this protein that reveals the presence of a free vinyl group on the porphyrin and a disulfide bond between the protomers and supports His-Met ligation in both valence states of the iron. A 3-A resolution x-ray structure shows that, in comparison with the native protein, the heme moiety is rotated 180 degrees about its alpha,gamma-axis; cysteine 14 has formed a thioether bond with the 2-vinyl of pyrrole ring I instead of the 4-vinyl of pyrrole ring II, as occurs in the native protein; and a cysteine 11 from each protomer has formed an intermolecular disulfide bond. Numerous, minor perturbations exist within the structure of rC(557) in comparison with that of native protein, which result from heme inversion and protein-protein interactions across the dimer interface. The unusual spectral properties of rC(557) are rationalized in terms of this structure. 相似文献